Perceptual Learning Treatment for Amblyopia

Amblyopia Clinical Trial

Official title:

Towards Developing a Perceptual Learning Treatment for Amblyopia

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT03788031
• Other study ID #: HSEARS20171108002
• Status: Active, not recruiting
• Phase: N/A
• Start date: March 1, 2019
• Est. completion date: February 28, 2023

Study information

• Verified date: August 2021
• Source: The Hong Kong Polytechnic University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Objectives. To develop a new treatment for amblyopia using a perceptual learning approach.

Hypothesis to be tested. Our proposed experiments are designed to investigate whether practicing a grating detection task can improve vision in patients with amblyopia.

Design and subjects. A total of 36 patients with amblyopia will be randomized allocated into two intervention groups: Group 1, perceptual learning therapy. Group 2, occlusion therapy. A control group comprising of 18 subjects with normal vision will be recruited for comparison. A battery of tests will be used to assess a range of visual functions before and after the treatment intervention.

Study instruments. Grating acuity testing system

Interventions. We have established a clinical protocol for acuity training. On each trial, a properly oriented stimulus will be presented randomly at one of the four locations on a flat monitor screen. The visual task is to indicate the location of the stimulus. Participants will be required to undertake 20 one-hour sessions of training.

Main outcome measures. Resolution acuity, visual acuity, contrast sensitivity function

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 54
• Est. completion date: February 28, 2023
• Est. primary completion date: December 31, 2022
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 7 Years and older

Eligibility

Inclusion Criteria:

• Visual acuity in the amblyopic eye: 20/25 or worse

Exclusion Criteria:

• Manifest eye disease & nystagmus

Related Conditions & MeSH terms

• Amblyopia

Intervention

Other:
• Acuity training
The intervention will be a vision therapy. On each trial, a properly oriented stimulus will be presented randomly at one of the four locations on a flat monitor screen. The visual task is to identify the location of the stimulus.
• Occlusion therapy
Participants will be required to patch the good eye for 20 days, 1 hour per day.

Locations

Country	Name	City	State
Hong Kong	Optometry Research Clinic	Hong Kong

Sponsors (1)

Lead Sponsor	Collaborator
The Hong Kong Polytechnic University

Country where clinical trial is conducted

Hong Kong, 

References & Publications (3)

Levi DM, Li RW. Improving the performance of the amblyopic visual system. Philos Trans R Soc Lond B Biol Sci. 2009 Feb 12;364(1515):399-407. doi: 10.1098/rstb.2008.0203. Review. — View Citation

Li RW, Klein SA, Levi DM. Prolonged perceptual learning of positional acuity in adult amblyopia: perceptual template retuning dynamics. J Neurosci. 2008 Dec 24;28(52):14223-9. doi: 10.1523/JNEUROSCI.4271-08.2008. — View Citation

Li RW, Ngo C, Nguyen J, Levi DM. Video-game play induces plasticity in the visual system of adults with amblyopia. PLoS Biol. 2011 Aug;9(8):e1001135. doi: 10.1371/journal.pbio.1001135. Epub 2011 Aug 30. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change of grating acuity	Grating acuity tests the participants' ability to resolve fine details. This study measures the change of grating acuity after 20 hours of vision training.	20 hours
Secondary	Change of visual acuity	Visual acuity tests the participants' ability to resolve letters.This study measures the change of visual acuity after 20 hours of vision training.	20 hours
Secondary	Change of contrast sensitivity	Contrast sensitivity reflects the participants' sensitivity to identify low contrast visual stimuli. This study measures the change of contrast sensitivity after 20 hours of vision training.	20 hours
Secondary	Change of stereopsis	Visual acuity tests the 3-D perception. This study measures the change of stereopsis after 20 hours of vision training.	20 hours